1. Field of the Invention
The present invention relates to a charged particle lithography apparatus, a vacuum chamber and a method of generating a vacuum in a vacuum chamber, for application in, for example, a lithography or inspection system.
2. Description of the Related Art
Charged particle and optical lithography machines and inspection machines are typically operated in a vacuum environment. This requires a vacuum chamber large enough to house the lithography machine or group of machines. The vacuum chamber must be sufficiently strong and vacuum tight to support the required vacuum, while having openings for electrical, optical and power cabling to enter the chamber, for the wafer or target to be loaded into the chamber, and to permit access to machine for maintenance and operational needs. Where charged particle machines are involved, the vacuum chamber must also provide shielding to prevent external electromagnetic fields from interfering with the operation of the machine.
Prior vacuum chamber designs have suffered from various drawbacks such as excessive weight relative to throughput of the lithography machine, excessive use of floor space, small size of the door, and poor electromagnetic shielding around the openings. Prior designs have required a costly and time-consuming fabrication process in the factory, usually requiring full assembly of the chamber before shipping to the site where it will be used, and high transport costs from the factory to the site where they are used.